E. with no birefringent sample present, the field of view is black. The ocular or eyepiece serves to magnify the image further. Often a magnification of q10 is used. The ocular also determines the field of view. Alternatively, after opening a shutter or by use of a semi-transmitting mirror, the image can also be projected onto a camera mounted on the microscope by an adjustable tube. High quality images are generally achieved simply with slide films. If a time resolved image acquisition is required to study dynamic effects, analog video cameras in combination with frame grabber hard- and software are used.